This invention relates generally to recording devices such as magnetic tape recorders and, particularly, those for use with tape cassettes. More particularly, the invention pertains to an automatic recording level control system for such recording devices featuring provisions for manual change of the standard level.
In tape recording, as is well known, the recording level or amplifier output level must be adjusted to secure a satisfactory recording, eliminating distortion due to too high a level and a decrease in signal to noise radio due to too low a level. Tape recorders are therefore usually equipped with a level control knob or knobs to be handled manually and a level indicator or indicators which show the voltage level or levels at which a recording is being made. The level control takes the form of a rheostat or adjustable attenuator.
The setting of the recording level by the manipulation of the level control knob can be troublesome to average users. A conventional solution to this problem has been a computer controlled, full automatic level control, as disclosed in Hasegawa et al. U.S. Pat. No. 4,352,130, which makes knob handling totally unnecessary. This seeming advantage of the prior art device, the complete exclusion of the user from the setting of the recording level, is its weakness at the same time. Just as an optimum setting to one user is not necessary so to another, so the setting made by the manufacturer for automatic level control may not be to the liking of the particular user of the recorder.